I haven't specified quantities as you can make as much or as little as you like - the method remains the same.

Prepare the spring onions:Once you've sliced the spring onions, heat a little butter in a small pan over a medium heat. When the butter has melted, add in the spring onions and sauté very briefly until the just begin to wilt - this should take somewhere between 30 seconds and a minute. Take them off the heat and set to one side.

Make the gratin:Take a casserole dish and layer it with turnip slices - sprinkle over with a little of the wilted onions, then repeat with another layer of turnips and onions - on every second layer add a little finely grated Parmigiano. You should finish with the turnips with a few pieces of onion poking through.

Pour cream and milk into a bowl and season lightly - whisk, the mixture should have the consistency of slightly thick milk. You can make this to your own preference, some will use just cream, some will use different combinations.

Carefully drizzle this over the turnips, it should just cover them. Finish the dish with an extra sprinkle of Parmigiano.

Place in a pre-heated 160ºC/320ºF oven until golden and bubbling and the turnips have softened.

Best served immediately.

I don't know if it's due to the variety of turnips used or the way they are cooked but these most definitely had a subtle taste of horseradish - combined with that creamy texture it had us dipping in for seconds!